Helicopter vibration active control method based on self-adaptive harmonic identification frequency response correction

Abstract

The invention discloses a helicopter vibration active control method based on self-adaptive harmonic identification frequency response correction, and aims to solve the problems of helicopter vibration active control effect reduction and even control divergence caused by helicopter body dynamics modeling errors of a helicopter in a helicopter vibration control process and change of a helicopter body frequency response function in helicopter flight. An adaptive harmonic recognition algorithm for correcting parameters of a frequency response function of a control system in real time according to a harmonic coefficient of a control error response signal is provided, so that the aim of actively controlling helicopter vibration under the condition that a helicopter modeling error is relatively large is fulfilled. The method has the advantages of being high in frequency response estimation precision, fast in control convergence, small in calculated amount, free of extra excitation and the like, and the control effects of being efficient, high in adaptability and fast in convergence can be achieved when the modeling error is large.

Description

technical field [0001] The invention belongs to the technical field of helicopter vibration control. Background technique [0002] Active vibration control technology is widely used in the field of vibration control of helicopters to meet the strict requirements for low vibration levels of helicopters. The realization of the traditional active vibration control algorithm depends on the accurate acquisition of the parameters of the dynamic model of the active vibration control system of the helicopter. The dynamic model of the active vibration control system of a helicopter is usually established through dynamic tests or wind tunnel experiments offline, so there are inevitably modeling errors. At the same time, factors such as changes in the flight state of the helicopter, changes in the load mass and the center of gravity will also cause changes in the dynamic model of the control system. In addition, for variable speed helicopters, the change of rotor load frequency cause...

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Problems solved by technology

However, the implementation of this type of algorithm often needs to introduce additional white noise excitation to realize the identification of the secondary channel, so the control effect will be reduced

In addition, the Adaptive Harmonic Steady State (AHSS) control algorithm based on high-order harmonic control can realize the frequency response identification of the control system in the frequency domain, but such algorithms rely on the discrete Fourier transform of the measured response data, and a sufficiently large time interval is required to ensure that the system response reaches a harmonic steady state

For the helicopter body structure with low damping and low natural frequency, the too long harmonic steady-state time interval of this type of control algorithm will lead to too long control convergence time, which cannot meet the high standard of helicopter vibration level requirements

At the same time, in order to realize the accurate identification of the frequency response function, this type of algorithm needs to continuously apply additional continuous excitation, which will also cause the control effect to decline

In addition, these algorithms usually require matrix inversion or matrix eigenvalue calculation. When the number of system control inputs and measuring point responses is large, the calculation amount of the algorithm will be greatly increased.

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